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Insects & invertebrates · Fungi

Leafcutter ant

They farm fungi, deploy antibiotics, and run cities underground—yet never leave the tropics of the Americas.

Worth your time?4.5/5Yes.See the whole thing.What works, what does not, who it is for ↓
9:08in productionCh. 1 · Where they come from/ 9:08 · ceiling 15 min
5 chapters · 9:08Ceiling 15:00

The brief is written and checked. The video joins this page when it is cut.5 chapters · 1 min read · 9:08 planned

Read the brief

Leafcutter ants are fungus-farming insects endemic to tropical Americas. They cut leaves to feed domesticated fungi. Their colonies reach 3.55 million individuals across 600 m². They bite with force 2600× body weight. They co-evolved with antibiotic-producing bacteria to protect crops. They do not eat leaves. They do not occur outside their native range. They are not generalists—they depend absolutely on specific fungi and bacteria.

Insects & invertebratesFungiAgricultureEcologyEvolutionAgriculture across the network →
Chapters & takeaways5
  1. 0:58
    Where they come from

    Fifty-five species. Three genera. One continent-wide range.

  2. 1:52
    What they actually do with leaves

    They cut leaves not to eat—but to feed fungi they cannot live without.

  3. 3:09
    How big their societies get

    Nests occupy up to 600 m² and house 3.55 million individuals—second only to humans in societal scale.

  4. 4:26
    How to tell them apart

    Atta has three spine pairs and smooth thorax; Acromyrmex has four and rough—visible without magnification.

  5. 5:34
    The full symbiosis

    They farm fungi, suppress parasites with bacteria, and build subterranean cities—all obligate, all interlocked.

2 more chaptersFewer chapters
Worth your time?

Yes. See the whole thing.

4.5/ 5
What works
  • farms fungi
  • suppresses Escovopsis with Pseudonocardia
  • builds nests housing up to 3.55 million individuals
  • carries up to 50× body weight
What does not
  • eat leaves
  • occur outside tropical Americas
  • farm non-Lepiotaceae fungi
See it if
  • ecologists
  • mycologists
  • field observers
Skip it if
  • temperate-zone naturalists
  • solitary-behaviour researchers
  • generalist-insect studies
Who should see it, and who should skipHide who it is for
The written brief1 min read

What the species is and where it came from

Leafcutter ants are at least 55 species across Atta, Acromyrmex, and Amoimyrmex—endemic to South and Central America, Mexico, and parts of the southern United States.

How it works, in terms someone would actually use

They cut fresh leaves, carry them up to 50× their body weight, and feed them to domesticated fungi in vast underground nests.

What it gets right

They reliably grow fungal gardens at scale. They suppress Escovopsis with Pseudonocardia bacteria. Their caste systems and nest architecture sustain up to 3.55 million individuals in 600 m².

What it does not

They do not eat the leaves they cut. They do not survive outside tropical Americas. They do not farm any fungus but Lepiotaceae—especially Leucoagaricus gongylophorus.

What it changed

They redefined cooperation: no other animal cultivates its food, maintains monoculture, farms bacteria for crop protection, and organises labour across millions without central command.

Who it is for, and who it is not

For ecologists, mycologists, and anyone who watches ants and wonders how a colony thinks. Not for those seeking solitary behaviour, wide dispersal, or temperate-range species.

Is it worth your time

Yes—if you want to see a non-human society that builds cities, farms, defends crops, and deploys antibiotics, all in soil.

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9:08
Honey beeHoney bees are eusocial flying insects in the genus Apis, native to Afro-Eurasia. They construct perennial cavity nests with hexagonal wax cells and store surplus carbohydrates as honey. Only Apis mellifera and Apis cerana are domesticated. Human-mediated dispersal has given them a cosmopolitan distribution excluding Antarctica. They are the most agriculturally valuable pollinators—but represent a small fraction of ~20,000 bee species.
9:19
MantisMantises are a globally distributed insect order defined by raptorial forelegs and ambush predation. Their stillness is functional—not symbolic. They share ancestry with cockroaches and termites. No conservation status or population data is provided. Their significance lies in anatomical consistency, not ecological exception.
9:29
Dung beetleDung beetles are not a species but a functional group—defined by what they eat and how they move it. They operate across continents, habitats, and behaviours. Their value is measurable: in soil, pasture, and myth. Their limits are clear: no cold, no aridity, no shared ancestry.
9:50
Weaver antWeaver ants are obligately arboreal eusocial insects in the genus Oecophylla, found in tropical and subtropical regions—especially southeast Asia—where they live exclusively in trees. Colonies can contain more than half a million workers across hundreds of nests spanning multiple trees. Workers construct nests by weaving leaves together using silk secreted by larvae. Major and minor workers show a clear bimodal size distribution and strictly divided roles: majors forage, defend, maintain, and expand; minors care for brood and milk scale insects for honeydew. They prey on small insects and aggressively defend territory. Though lacking a sting, they inflict painful bites and spray formic acid directly at the wound. Indigenous farmers in southeast Asia use them as natural biocontrol agents against agricultural pests.
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